Tool to aid in fireplace flue installation

ABSTRACT

The tool to aid in fireplace flue installation supports the sections of a flue during attachment to the vent of a fireplace or stove. The tool has a support bracket for mounting the tool to a vertical support, such as a stud in a chase where the flue will be installed. Attached to the support bracket is an arm support member, which holds a plurality of flue support arms. The flues support arms are pivotally attached to the support member so that the arms rotate about a vertical axis. Each support arm can be rotated independently of the other support arm or arms. The support arms are provided with setscrews, which are tightened to lock the support arms into a selected position. Each support arm may be provided with an arm extension, which slidably engages the support arm, allowing the overall length of the arm to be extended.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to the installation of flues for stoves and fireplaces, and more particularly to a tool to aid in fireplace flue installation that is useful for supporting metal flue pipes during the installation of prefabricated fireplaces, particularly double wall flues.

2. Description of the Related Art

A properly installed flue is a vital element of fireplaces and stoves, which burn wood, coal or gas to provide heat. The flue provides a mechanism for removing carbon monoxide and other combustion products so that they do not accumulate in the building in which the stove is installed. Providing a proper draft to insure that the waste gases are vented up the flue rather than into the room requires that the flue be maintained at a high temperature to provide a convection flow. Low flue temperatures can also result in the condensation of combustion byproducts, such as creosote, inside the flue. Because creosote is highly flammable in the condensed state, the accumulation of creosote in the flue presents a significant fire hazard. Creosote fires burn extremely hot and can quickly raise flue temperatures to the point where nearby combustible materials can catch fire.

However high flue temperatures can also create a fire hazard. When single wall flue systems are used, it is necessary to provide relatively large spacing between the flue and combustible materials used to construct floors, walls, and ceilings. The required spacing can be as much as eighteen inches, depending upon the type of fireplace and the expected flue temperatures. Very often providing the large amount of required spacing around the flue restricts the placement of the stove or fireplace.

One solution is to use a double wall insulated flue system. Double wall systems have an inner wall that operates at a high temperature, providing the proper drafting and temperatures to remove poisonous combustion gases and to prevent the accumulation of creosote, as well as a cooler outer wall. The outer wall is separated from the inner wall either by an air gap or by thermal insulation material so that the outer wall is kept relatively cool. The low temperature of the outer wall allows the double wall flue system to be installed with significantly smaller clearances to adjoining structures made from combustible material than in the installation of a single wall system. In some double wall flue systems, a clearance of several inches from combustible materials may be sufficient to protect the combustible materials from ignition due to the operating temperature of the flue.

The walls of double wall flue systems are normally constructed of corrosion resistant materials, such as aluminum, stainless steel, galvanized steel, or other steels with coated with corrosion-resistant coatings, such as aluminum and/or zinc. Often the inner wall, which is in contact with corrosive combustion by-products at high temperature, is constructed of material of superior corrosion resistance while the outer wall can be of a more economical material having less resistance to corrosion.

Installing double wall flue systems can present a number of challenges. In a typical installation, the flue is installed in a chase extending from the stove or fireplace up through the roof. The flue generally extends several feet above the roof, making the assembled flue relatively heavy. In a typical installation, the assembled double wall flue may be twenty-eight or more feet in height and weigh over one hundred pounds. The flue is assembled from sections to obtain the desired height. For example the flue may comprise a number of 48-inch high sections plus a final section shorter than forty-eight inches.

Generally, the flue is installed prior to placement of the fireplace or stove. Thus it is desirable to suspend the flue above the installation point during assembly and prior to connecting the flue to a fireplace or stove. A typical chase may be about four feet in width and have a narrow cross section, presenting a cramped working space for the installer. The available structure for supporting a flue in the chase is generally limited to structure studs on 18-inch centers. The studs can be used to support a device for suspending a flue, but because the studs are spaced apart at 18-inch intervals, the studs may not be at a convenient location for supporting the flue directly over the connection point on a fireplace.

Some installers use a simple hook nailed to a stud in the chase to support the flue. The hook solution suffers from the placement problem described above, and has some limitations, which make the solution not the most optimal. Because the two sections of the flue are supported by a single hook, the entire flue must be moved in order to connect the inner wall of the flue to the fireplace. The geometry of the hook requires lifting the entire flue an appreciable distance in order to separate the inner and outer walls. When the flue system is lifted, the hook remains in the path of the flue and is an obstacle to installing the inner flue wall. Usually this problem is solved by moving the hook out of the way while attaching the first flue wall to the fireplace. Since the support system is removed, two people are required to complete the installation. A first person attaches the inner wall to the vent opening of the stove while a second person holds the outer wall. The cramped quarters in the chase make it desirable to eliminate the need for the second person.

Several devices have been developed or proposed for supporting flue pipes. German Patent No. 19,742,689, published Dec. 12, 1999, describes a support system for a double wall flue using coupling elements comprising a telescoping device extending between the flue walls. European Patent No. 289,783, published Nov. 9, 1988, describes an apparatus for supporting a flue pipe in a chimney during lowering of the flue for installation.

None of the above inventions and patents, taken either singly or in combination, is seen to describe the instant invention as claimed. Thus, a tool to aid in fireplace flue installation solving the aforementioned problems is desired.

SUMMARY OF THE INVENTION

The tool to aid in fireplace flue installation supports the sections of a flue during assembly to the vent of a fireplace or stove. The tool has a support bracket for mounting the tool to a vertical support, such as a stud in a chase where the flue will be installed. Attached to the support bracket is an arm support member, which holds a plurality of flue support arms. The flues support arms are pivotally attached to the support member so that the arms rotate about a vertical axis. Each support arm can be rotated independently of the other support arm or arms. The support arms are provided with setscrews, which are tightened to lock the support arms into a selected position.

Each support arm may be provided with an arm extension, which slidably engages the support arm, allowing the overall length of the arm to be extended. The support arms are provided with a second setscrew that engages the arm extension and allows the arm extension to be locked at a selected length.

The tool is particularly useful for installing a double wall flue system. During installation, each of the walls of the flue system is supported separately by a support arm and an arm extension. Because the walls are separately supported, each wall of the flue can be independently lowered and attached to the vent opening of a stove or fireplace while the remaining uninstalled wall continues to be supported by the tool.

The support bracket is provided with keyhole slots for attaching the bracket to a stud. The bracket is attached to the stud by nails and is easily removed once the flue installation is complete.

The flue support arms may extend from the vertical axis of the tool at a small angle above the horizontal plane. This small angle helps prevent the walls of the flue from sliding off of the tool during assembly of the flue from sections, and during attachment of the flue to the vent opening of a stove or fireplace.

The flue arm extension may have a catch located at the end of the arm extension. The catch engages a wall of the flue and helps to prevent the wall from shifting on the support arm if the flue wall is bumped or disturbed.

These and other features of the present invention will become readily apparent upon further review of the following specification and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an environmental, perspective view of a tool to aid in fireplace flue installation according to the present invention.

FIG. 2 is an environmental perspective view of the tool of the present invention with one support arm pivoted away from the work area.

FIG. 3 is a perspective view showing details of a support arm of the flue installation tool.

Similar reference characters denote corresponding features consistently throughout the attached drawings.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention is a tool for supporting a flue system during installation. Details of the tool for installing a fireplace flue system in accordance with the invention will be described with reference to FIGS. 1-3.

FIG. 1 shows the fireplace flue installation tool 20 supporting the inner wall 38 and outer wall 36 of a twin-wall fireplace flue system. The flue installation tool 20 comprises a support bracket 28. The support bracket supports an upper arm 22 a and a lower arm 22 b. The upper and lower arms 22 a and 22 b are pivotally attached to a support member 34 (shown in FIG. 3) attached to the support bracket 28, which allows the upper and lower arms 22 a and 22 b to rotate around a vertical axis.

In use, the bracket 28 is mounted within the chase in which it is desired to install a fireplace flue to a stationary support, such as a vertical stud 30. The bracket 28 is provided with keyhole slots 26 for mounting the bracket 28 to the stud 30. The keyhole slots allow the bracket 28 to be secured to the stud 30 using nails 32, and also allow the bracket 28 to be easily lifted off of the nails 32 when installation of the flue is complete.

The keyhole dimensions are selected so that the slot portion of the keyhole is large enough to accommodate the shaft of a nail used to mount the tool, while the circular portion of the keyhole is smaller than the head of the nail so that the bracket is held securely to the mounting surface. Preferably the keyhole is sized to accommodate a 16-penny nail (size 16d).

The upper 22 a and lower 22 b arms are each provided with an extension rod 24 a and 24 b, which slidably engages the respective support arms 22 a and 22 b to provide flue section supporting arms of adjustable length. A setscrew or thumbscrew 44 secures the respective extensions 24 a and 24 b to temporarily fix the length of each support arm to adjust for the diameter of the flue pipes. FIG. 3 shows details of a support arm 22 and an arm extension 24. The vertical separation distance between the upper and lower support arms determines the vertical separation between the inner and outer flue walls when the tool supports a double wall flue. Preferably the separation distance is chosen to allow enough separation to expose enough of the inner wall to provide a grip for the installer when lifting the inner wall of the flue off of the lower support arm and extension. The separation distance is also chosen to minimize the movement required to access the outer wall when finalizing the installation.

As shown in FIG. 3, the support arm 22 is provided with a setscrew that engages the arm extension 24. The arm extension is provided with a flat surface 50 to provide an increased contact area for engaging the setscrew. In use, the arm extension 24 slides within the support arm 22 and is extended to provide the required length for supporting one wall of the flue without interfering with the motion of the other flue wall. Once the arm extension 24 is adjusted to the required length, the setscrew is tightened to lock the arm extension 24 at the selected length.

The arm extension 24 may be provided with a catch 48 near the end of the arm extension opposite the flue support arm 22. The catch 48 is a protrusion extending substantially vertically from the arm extension 24. The catch 48 provides additional support to the flue so that accidental contact or bumping of the flue does not cause the flue to fall off of the supporting arm. The catch 48 may be a short vertical rod or pin. When the arm extension 24 is supporting a flue wall, the catch 48 engages the inside surface of the flue wall preventing the wall from sliding off of the arm extension if the flue is bumped or disturbed.

Each support arm 22 is made from a vertical tube 58, a tubular arm extending normal to the vertical tube 58 about midway along the length of the vertical tube 58, and a generally triangular gusset plate 56. The support arm 22 is provided with a positioning setscrew 46, which engages the vertical axle 34 about which the support arm 22 rotates to temporarily fix the angular rotation of the support arm 22 about the vertical axle 34. The setscrew threads into a vertical section 58 of the support arm which is concentric with the vertical axle. Once the arm is positioned so that the arm and extension support a section of the flue to be installed, the positioning setscrew 46 is tightened to lock the arm into the selected orientation. The arm can be unlocked by loosening the positioning setscrew 46 when it is desired to move the support arm 22 and the arm extension 24 out of the path of the flue section so that the flue section can be attached to a fireplace or stove.

Preferably the support arms 22 and the arm extension 24 are supported on the bracket 28 at a small angle above horizontal. The small upward angle assists in maintaining the flue sections 36 and 38 in position on the support arm and the extension. Typical angles for the support arm and arm extension are 5°-20° above the horizontal. Alternatively, the support arm 22 may be horizontal or even angled slightly below horizontal. Angles outside of the above-specified ranges may also be employed.

FIG. 2 shows the flue installation tool 20 in position after the inner flue section 38 has been installed. The lower tool arm 22 b and lower extension 24 b have been positioned away from the inner flue wall by loosening the positioning setscrew 46 and rotating the lower support arm 22 b out of the way. The inner flue section 38 has been lowered and attached to the flue vent 54 of the fireplace 52. The upper tool arm and upper arm extension continue to support the outer flue section. Installation of the flue is completed by loosening the positioning setscrew 46 for the upper arm 22 a and rotating the upper arm 22 a out of the path of the outer flue wall so that the outer flue wall can be lowered and attached to the vent opening 54 of the fireplace.

In an alternate embodiment, the tool may comprise more than two support arms. For example, a three-armed tool would provide independent support for each of the-walls of a triple-wall flue system. If desired, the tool may comprise a single support arm for installation of a single wall flue pipe.

In an exemplary embodiment, the bracket 28 and support arms 22 are made of steel. The support arms 22 pivot on,a single vertical axle 34, which may be a long bolt or rod with threaded ends secured between upper 42 and lower 40 angle brackets fixed to support bracket 28. The support arms 22 are separated on the axle 34 by a washer or bearing so that the arms 22 a and 22 b can rotate independently on the axle 34. The horizontally extending portion of the support arms 22 are separated by a vertical distance of about five inches. The length of the upper arm 22 a is about ten inches while the lower arm 22 b is about twelve inches long. The difference in length accommodates the nesting of the inner and outer walls of a double wall flue. The support arms 22 and the arm extensions 24 may be at an angle of about 5° to 10° above horizontal. The dimensions are representative and provided for enablement purposes and do not limit the invention to the particular dimensions described.

It is to be understood that the present invention is not limited to the embodiments described above, but encompasses any and all embodiments within the scope of the following claims. 

1. A tool to aid in fireplace flue installation, comprising: an elongated support bracket adapted for attachment to a wall stud adjacent a fireplace installation; an elongated support rod attached to the support bracket; at least one support arm pivotally mounted on the support rod, the support arm having a flue supporting member extending transverse to the support rod adapted for supporting a flue pipe; and means for selectively locking the support arm with the flue supporting member at a desired angle of rotation about the support rod.
 2. The tool according to claim 1, wherein said support bracket has at least one keyhole slot defined therein adapted for hanging the support bracket on a nail driven into the wall stud.
 3. The tool according to claim 1, wherein the flue supporting member extends at an acute angle relative to the support rod, whereby the flue supporting member is adapted for sloping upward above the fireplace installation.
 4. The tool according to claim 1, wherein said flue supporting member comprises an extendable member including a base member and an extension member slidable within the base member in telescoping manner, the extension arm being extendable from the base member.
 5. The tool according to claim 4, wherein said at least one supporting arm further comprises a length adjustment screw extendable through the base member in order to releasably clamp the extension arm, thereby temporarily fixing the flue supporting member at a selectable length.
 6. The tool according to claim 5, wherein said at least one support arm comprises two support arms and a bearing disposed between the two support arms, whereby the support arms are independently rotatable about the support rod.
 7. The tool according to claim 1 wherein the means for locking comprises a setscrew mounted in said support arm and selectively extendable to engage said support rod.
 8. The tool according to claim 1, further comprising a catch mounted on the flue supporting member and extending normal to the flue supporting member adapted for preventing the flue pipe from sliding off the flue support member.
 9. The tool according to claim 8, wherein said catch comprises a pin.
 10. The tool according to claim 1, wherein said flue supporting member comprises a base tube, said support arm having a support rod tube transverse to the base tube rotatably disposed on the support rod for pivoting said support arm.
 11. The tool according to claim 10, wherein said support arm further comprises a gusset plate extending between the support rod tube and the base tube.
 12. A tool to aid in fireplace flue installation, comprising: an elongated support bracket adapted for attachment to a wall stud adjacent a fireplace installation in a vertical orientation; an elongated support rod attached to the support bracket and extending parallel to the support bracket; a first support arm and a second support arm, each of the support arms having a vertically oriented tube rotatably disposed on the support rod and a tubular arm extending substantially normal to the vertically oriented tube, the tubular arm being adapted for supporting a flue pipe, the vertically oriented tubes of the first and second arms being sequentially stacked on the support rod, the tubular arms having different lengths; a bearing disposed on the support rod between the first and second support rods; and first and second setscews selectively extendable through the vertical tubes of the first and second support arms, respectively, for selectively clamping the support arm to the support rod; whereby the first and second support arms are adapted for supporting inner and outer walls of a double wall flue pipe above the fireplace installation and independently rotatable for sequential installation of the inner and outer walls.
 13. The tool according to claim 12, wherein said tubular arm comprises a telescoping tubular arm and locking means for adjusting the telescoping arm at a selectable length.
 14. The tool according to claim 12, further comprising a pin extending normal from an end of the tubular arm of each of said support arms, the pin being adapted for retaining the flue pipe on said support arms. 